Omega cycloalkyl 17-heteroaryl prostaglandin E2 analogs as EP2-receptor agonists

ABSTRACT

The invention relates to the use of derivatives of E-type prostaglandins as EP 2  agonists, in general, and, in particular as ocular hypotensives. The PGE derivatives used in accordance with the invention are represented by the following formula I: 
                         
wherein the hatched segment represents an α bonds, the solid triangle represents a β bond, the wavy segments represent α or β bond, dashed lines represent a double bond or a single bond, X is selected from the group consisting of hydrogen and halogen radicals, R 3  is heteroaryl or a substituted heteroaryl radical, R 1  and R 2  are independently selected from the group consisting of hydrogen or a lower alkyl radical having up to six carbon atoms, or a lower acyl radical having up to six carbon atoms, R is selected from the group consisting of CO 2 R 4 , CONR 4   2 , CH 2 OR 4 , CONR 4 SO 2 R 4 , P(O)(OR 4 ) and
 
                         
wherein R 4  is selected from the group consisting of H, phenyl and lower alkyl having from one to six carbon atoms and n is 0 or an integer of from 1 to 4.

This Application is a continuation of application Ser. No. 10/283,629,filed Oct. 29, 2002, now U.S. Pat. No. 6,710,072 B2, and claims thebenefit of U.S. Provisional Application No. 60/338,838, filed Nov. 5,2001, hereby incorporated by reference herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to ω-cycloalkyl 17-heteroarylprostaglandin E₂ analogs as EP₂-receptor agonists. These compounds arepotent ocular hypotensive and are particularly suited for the managementof glaucoma.

2. Description of Related Art

Ocular hypotensive agents are useful in the treatment of a number ofvarious ocular hypertensive conditions, such as post-surgical andpost-laser trabeculectomy ocular hypertensive episodes, glaucoma, and aspresurgical adjuncts.

Glaucoma is a disease of the eye characterized by increased intraocularpressure. On the basis of its etiology, glaucoma has been classified asprimary or secondary. For example, primary glaucoma in adults(congenital glaucoma) may be either open-angle or acute or chronicangle-closure. Secondary glaucoma results from pre-existing oculardiseases such as uveitis, intraocular tumor or an enlarged cataract.

The underlying causes of primary glaucoma are not yet known. Theincreased intraocular tension is due to the obstruction of aqueous humoroutflow. In chronic open-angle glaucoma, the anterior chamber and itsanatomic structures appear normal, but drainage of the aqueous humor isimpeded. In acute or chronic angle-closure glaucoma, the anteriorchamber is shallow, the filtration angle is narrowed, and the iris mayobstruct the trabecular meshwork at the entrance of the canal ofSchlemm. Dilation of the pupil may push the root of the iris forwardagainst the angle, and may produce pupilary block and thus precipitatean acute attack. Eyes with narrow anterior chamber angles arepredisposed to acute angle-closure glaucoma attacks of various degreesof severity.

Secondary glaucoma is caused by any interference with the flow ofaqueous humor from the posterior chamber into the anterior chamber andsubsequently, into the canal of Schlemm. Inflammatory disease of theanterior segment may prevent aqueous escape by causing completeposterior synechia in iris bombe, and may plug the drainage channel withexudates. Other common causes are intraocular tumors, enlargedcataracts, central retinal vein occlusion, trauma to the eye, operativeprocedures and intraocular hemorrhage.

Considering all types together, glaucoma occurs in about 2% of allpersons over the age of 40 and may be asymptotic for years beforeprogressing to rapid loss of vision. In cases where surgery is notindicated, topical β-adrenoreceptor antagonists have traditionally beenthe drugs of choice for treating glaucoma.

Certain eicosanoids and their derivatives have been reported to possessocular hypotensive activity, and have been recommended for use inglaucoma management. Eicosanoids and derivatives include numerousbiologically important compounds such as prostaglandins and theirderivatives. Prostaglandins can be described as derivatives ofprostanoic acid which have the following structural formula:

Various types of prostaglandins are known, depending on the structureand substituents carried on the alicyclic ring of the prostanoic acidskeleton. Further classification is based on the number of unsaturatedbonds in the side chain indicated by numerical subscripts after thegeneric type of prostaglandin [e.g. prostaglandin E₁ (PGE₁),prostaglandin E₂ (PGE₂)], and on the configuration of the substituentson the alicyclic ring indicated by α or β [e.g. prostaglandin F_(2α)(PGF_(2α))].

Prostaglandins were earlier regarded as potent ocular hypertensives,however, evidence accumulated in the last decade shows that someprostaglandins are highly effective ocular hypotensive agents, and areideally suited for the long-term medical management of glaucoma (see,for example, Bito, L. Z. Biological Protection with Prostaglandins,Cohen, M. M., ed., Boca Raton, Fla., CRC Press Inc., 1985, pp. 231-252;and Bito, L. Z., Applied Pharmacology in the Medical Treatment ofGlaucomas Drance, S. M. and Neufeld, A. H. eds., New York, Grune &Stratton, 1984, pp. 477-505. Such prostaglandins include PGF_(2α),PGF_(1α), PGE₂, and certain lipid-soluble esters, such as C₁ to C₂ alkylesters, e.g. 1-isopropyl ester, of such compounds.

Although the precise mechanism is not yet known experimental resultsindicate that the prostaglandin-induced reduction in intraocularpressure results from increased uveoscleral outflow [Nilsson et. al.,Invest. Ophthalmol. Vis. Sci. (suppl), 284 (1987)].

The isopropyl ester of PGF_(2α) has been shown to have significantlygreater hypotensive potency than the parent compound, presumably as aresult of its more effective penetration through the cornea. In 1987,this compound was described as “the most potent ocular hypotensive agentever reported” [see, for example, Bito, L. Z., Arch. Ophthalmol. 105,1036 (1987), and Siebold et. al., Prodrug 5 3 (1989)].

Whereas prostaglandins appear to be devoid of significant intraocularside effects, ocular surface (conjunctival) hyperemia and foreign-bodysensation have been consistently associated with the topical ocular useof such compounds, in particular PGF_(2α) and its prodrugs, e.g., its1-isopropyl ester, in humans. The clinical potentials of prostaglandinsin the management of conditions associated with increased ocularpressure, e.g. glaucoma are greatly limited by these side effects.

In a series of co-pending United States patent applications assigned toAllergan, Inc. prostaglandin esters with increased ocular hypotensiveactivity accompanied with no or substantially reduced side-effects aredisclosed. The co-pending U.S. Ser. No. 596,430 (filed 10 Oct. 1990),now U.S. Pat. No. 5,446,041, relates to certain 11-acyl-prostaglandins,such as 11-pivaloyl, 11-acetyl, 11-isobutyryl, 11-valeryl, and11-isovaleryl PGF_(2α). Intraocular pressure reducing 15-acylprostaglandins are disclosed in the co-pending application U.S. Ser. No.175,476 (filed 29 Dec. 1993). Similarly, 11,15-9,15- and 9,11-diestersof prostaglandins, for example 11,15-dipivaloyl PGF_(2α) are known tohave ocular hypotensive activity. See the co-pending patent applicationU.S. Ser. No. 385,645 (filed 7 Jul. 1989, now U.S. Pat. No. 4,994,274),U.S. Ser. No. 584,370 (filed 18 Sep. 1990, now U.S. Pat. No. 5,028,624)and U.S. Ser. No. 585,284 (filed 18 Sep. 1990, now U.S. Pat. No.5,034,413). The disclosures of all of these patent applications arehereby expressly incorporated by reference.

SUMMARY OF THE INVENTION

The present invention concerns a method of treating ocular hypertensionwhich comprises administering to a mammal having ocular hypertension atherapeutically effective amount of a compound of formula I

wherein the hatched segment represents an α bond, the solid trianglerepresents a β bond, the wavy segment represents α or β bond, dashedlines represent a double bond or a single bond, X is hydrogen or a haloradical, e.g. a fluoro or chloro radical, R³ is heteroaryl or asubstituted heteroaryl radical, R¹ and R² are independently selectedfrom the group consisting of hydrogen or a lower alkyl radical having upto six carbon atoms, or a lower acyl radical having up to six carbonatoms, R is selected from the group consisting of CO₂R⁴, CONR⁴ ₂,CH₂OR⁴, CONR⁴SO₂R⁴, P(O)(OR⁴) and

wherein R⁴ is selected from the group consisting of H, phenyl and loweralkyl having from one to six carbon atoms and n is 0 or an integer offrom 1 to 4.

In a further aspect, the present invention relates to an ophthalmicsolution comprising a therapeutically effective amount of a compound offormula (I), wherein the symbols have the above meanings, or apharmaceutically acceptable salt thereof, in admixture with a non-toxic,ophthalmically acceptable liquid vehicle, packaged in a containersuitable for metered application. In particular, the substituents on theheteroaryl radical may be selected from the group consisting of loweralkyl, e.g. C₁ to C₆ alkyl; OR⁴; CO₂R⁴; halogen, e.g. fluoro, chloro andbromo; trifluoromethyl (CF₃); COR⁴, e.g. COCH₃; COCF₃; SO₂NR⁴, e.g.SO₂NH₂; NO₂; CN; etc.

In a still further aspect, the present invention relates to apharmaceutical product, comprising

-   -   a container adapted to dispense its contents in a metered form;        and    -   an ophthalmic solution therein, as hereinabove defined.

Finally, certain of the compounds represented by the above formula,disclosed below and utilized in the method of the present invention arenovel and unobvious.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

FIG. 1 is a schematic of the chemical synthesis of certain compoundsrelated to the compounds of the invention, as specifically disclosed inExamples 12H and L and 13H and L.

FIG. 2 is a schematic of the chemical synthesis of certain compoundsrelated to the compounds of the invention, as specifically disclosed inExamples 16H and L and 17H and L.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to the use of ω-cycloalkyl 17-heteroarylprostaglandin E₂ analogs as EP₂-receptor agonists. The compounds used inaccordance with the present invention are encompassed by the followingstructural formula I:

wherein the substituents and symbols are as hereinabove defined. Thedotted lines on bonds between carbons 5 and 6 (C-5) and carbons 13 and14 (C-13) indicate a single or double bond. If two solid lines are usedat C-5, or C-13, it indicates a specific configuration for that doublebond. Hatched lines used at position C-8, C-9 and C-1 indicate the αconfiguration. A triangle at position C-12 represents β orientation.

A preferred group of the compounds of the present invention includescompounds that have the following structural formula II:

wherein Z is selected from the group consisting of O and S, A isselected from the group consisting of N, —CH, and C, R⁵ is selected fromthe group consisting of hydrogen, halogen, lower alkyl having from 1 to6 carbon atoms and lower alkoxy having from 1 to 6 carbon atoms, R⁶ andR⁷ are selected from the group consisting of hydrogen, halogen, loweralkyl having from 1 to 6 carbon atoms and lower alkoxy having from 1 to6 carbon atoms, or, together with,

R⁶ and R⁷ forms a condensed aryl ring.Another preferred group includes compounds having the formula III:

In the above formulae, the substituents and symbols are as hereinabovedefined.

The above compounds of the present invention may be prepared by methodsthat are known in the art or according to the working examples below.

The compounds, below, are especially preferred representative of thecompounds of the present invention.

-   7-{(1R,2R,3R)-3-Hydroxy-2-[(E)-4-hydroxy-4-(1-(5-chloro-thiophen-2-yl)-methyl-cyclobutyl)but-1-enyl]-5-chloro-cyclopentyl}hept-5-enoic    acid methyl ester-   7-{(1R,2R,3R)-3-Hydroxy-2-[(E)-4-hydroxy-4-(1-(5-chloro-thiophen-2-yl)-methylcyclobutyl)but-1-enyl]-5-chlorocyclopentyl}hept-5-enoic    acid-   (Z)-7-{(1R,2R,3R)-3-Hydroxy-2-[(E)-4-hydroxy-4-(1-(5-chloro-thiophen-2-yl)-methylcyclobutyl)but-1-enyl]-5-fluoro-cyclopentyl}hept-5-enoic    acid methyl ester-   (Z)-7-{(1R,2R,3R)-3-Hydroxy-2-[(E)-4-hydroxy-4-(1-(5-chloro-thiophen-2-yl-methylcyclobutyl)but-1-enyl]-5-fluoro-cyclopentyl}hept-5-enoic    acid-   (Z)-7-{(1R,2R,3R)-3-Hydroxy-2-[(E)-4-hydroxy-4-(1-(5-chloro-thiophen-2yl)-methylcycolobutyl)but-1-enyl]cyclopentenyl}hept-5-enoic    acid methyl ester-   (Z)-7-{(1R,2R,3R)-3-Hydroxy-2-[(E)-4-hydroxy-4-(1-(5-chloro-thiophen-2yl)-methylcycobutyl)but-1-enyl]cyclopentenyl}hept-5-enoic    acid

A pharmaceutically acceptable salt is any salt which retains theactivity of the parent compound and does not impart any deleterious orundesirable effect on the subject to whom it is administered and in thecontext in which it is administered. Of particular interest are saltsformed with inorganic ions, such as sodium, potassium, calcium,magnesium and zinc.

Pharmaceutical compositions may be prepared by combining atherapeutically effective amount of at least one compound according tothe present invention, or a pharmaceutically acceptable acid additionsalt thereof, as an active ingredient, with conventional ophthalmicallyacceptable pharmaceutical excipients, and by preparation of unit dosageforms suitable for topical ocular use. The therapeutically efficientamount typically is between about 0.0001 and about 5% (w/v), preferablyabout 0.001 to about 1.0% (w/v) in liquid formulations.

For ophthalmic application, preferably solutions are prepared using aphysiological saline solution as a major vehicle. The pH of suchophthalmic solutions should preferably be maintained between 6.5 and 7.2with an appropriate buffer system. The formulations may also containconventional, pharmaceutically acceptable preservatives, stabilizers andsurfactants.

Preferred preservatives that may be used in the pharmaceuticalcompositions of the present invention include, but are not limited to,benzalkonium chloride, chlorobutanol, thimerosal, phenylmercuric acetateand phenylmercuric nitrate. A preferred surfactant is, for example,Tween 80. Likewise, various preferred vehicles may be used in theophthalmic preparations of the present invention. These vehiclesinclude, but are not limited to, polyvinyl alcohol, povidone,hydroxypropyl methyl cellulose, poloxamers, carboxymethyl cellulose,hydroxyethyl cellulose and purified water.

Tonicity adjustors may be added as needed or convenient. They include,but are not limited to, salts, particularly sodium chloride, potassiumchloride, mannitol and glycerin, or any other suitable ophthalmicallyacceptable tonicity adjustor.

Various buffers and means for adjusting pH may be used so long as theresulting preparation is ophthalmically acceptable. Accordingly, buffersinclude acetate buffers, citrate buffers, phosphate buffers and boratebuffers. acids or bases may be used to adjust the pH of theseformulations as needed.

In a similar vein, an ophthalmically acceptable antioxidant for use inthe present invention includes, but is not limited to, sodiummetabisulfite, sodium thiosulfate, acetylcysteine, butylatedhydroxyanisole and butylated hydroxytoluene.

Other excipient components which may be included in the ophthalmicpreparations are chelating agents. The preferred chelating agent isedentate disodium, although other chelating agents may also be used inplace or in conjunction with it.

The ingredients are usually used in the following amounts:

Ingredient Amount (% w/v) active ingredient about 0.001–5      preservative   0–0.10 vehicle 0–40 tonicity adjustor 1–10 buffer0.01–10   pH adjustor q.s. pH 4.5–7.5 antioxidant as needed surfactantas needed purified water as needed to make 100%

The actual dose of the active compounds of the present invention dependson the specific compound, and on the condition to be treated; theselection of the appropriate dose is well within the knowledge of theskilled artisan.

The ophthalmic formulations of the present invention are convenientlypackaged in forms suitable for metered application, such as incontainers equipped with a dropper, to facilitate the application to theeye. Containers suitable for dropwise application are usually made ofsuitable inert, non-toxic plastic material, and generally containbetween about 0.5 and about 15 ml solution.

The invention is further illustrated by the following non-limitingExamples, which are summarized in the reaction schemes of FIGS. 1 and 2,wherein the compounds are identified by the same designator in both theExamples and the Figures.

EXAMPLE 1 ethyl Cyclobutanecarboxylate acid ethyl ester (1)

The named compound was purchased from Aldrich Chemical Co., P.O. Box2060, Milwaukee, Wis. 53201 USA.

EXAMPLE 2 1-(1-Hydroxy-1-thiophen-2-yl-methyl)cyclobutanecarboxylic acidethyl ester (2)

Lithium diisopropylamide mono(THF) (1.95 mL of a 2.0M solution inheptane/THF/ethylbenzene, 3.90 mmol) was added to a solution of ester 1(0.50 g, 3.9 mmol) in THF (6 mL) at −78° C. After stirring 30 min,2-thiophenecarboxaldehyde (667 mg, 5.95 mmol) was added and the mixturewas stirred for 3 h. After the reaction was judged complete by TLCanalysis, saturated aqueous NH₄Cl was added and the reaction was slowlywarmed to 23° C. The THF was evaporated and the reaction mixture wasextracted with CH₂Cl₂ (2×). The combined organic layers were washed withbrine, dried (Na₂SO₄), filtered and concentrated in vacuo. Purificationof the residue by flash column chromatography (FCC) (silica gel, 100%hexane followed by 9:1 hexane/EtOAc) afforded the above named compound2.

EXAMPLE 3 1-Thiophen-2-yl-methylcyclobutanecarboxylic acid ethyl ester(3)

Trimethylsilyliodide (20 g, 100 mmol) was added to CH₃CN (10 mL) at 0°C. and the mixture was allowed to stir 5 min. A solution of alcohol 2 (5g, 20 mmol) in CH₃CN (10 mL) was added slowly while the temperature waskept between 4-10° C. and the reaction was allowed to warm to 23° C.After stirring for 2 h at 23° C. the reaction was judged complete viaTLC analysis. The mixture was poured into 3N NaOH at 0° C. and EtOAc wasadded. The organic layer was separated, washed with brine, dried(Na₂SO₄), filtered and concentrated in vacuo. FCC (silica gel, 1:1hexane/CH₂Cl₂) gave 2.3 g of the above named ester 3.

EXAMPLE 4 (1-Thiophen-2-yl-methylcyclobutyl)methanol (4)

Lithium borohydride (435 mg, 20 mmol) was added to a solution of ester 3(2.3 g, 10 mmol) in Et₂O (20 mL) at 0° C. After having stirred for 5min, MeOH (640 mg, 20 mmol) was added dropwise and stirring continued at0° C. until effervescence ceased. The mixture was warmed to 23° C. andwas allowed to stir an additional hour, at which time the mixture waspoured into 3N NaOH and stirred an additional 0.5 h. The organic layerwas separated and washed with brine, dried (Na₂SO₄), filtered andconcentrated in vacuo. The crude alcohol 4 was purified by FCC (silicagel, 1:1 hexane/CH₂Cl₂).

EXAMPLE 5 1-Thiophen-2-yl-methylcyclobutanecarbaldehyde (5)

Oxalyl chloride (50 mL, 0.10 mmol) was added to CH₂Cl₂ (150 mL) at 23°C. and was cooled to −78° C. DMSO (16 g, 0.20 mmol) was added dropwiseto the mixture and stirring was continued for 15 min. A solution ofalcohol 4 (7.9 g, 0.041 mmol) in CH₂Cl₂ (50 mL) was then added dropwise,after which Et₃N (44 g, 0.44 mmol) was added and the mixture was warmedto 23° C. After 1 h, the mixture was poured into saturated aqueousNaHCO₃ and the organic layer was separated. The aqueous layer wasextracted with CH₂Cl₂ (2×) and the combined organic portions were washedwith brine, dried (Na₂SO₄), concentrated in vacuo and purified by FCC(silica gel, 100% hexane followed by 2:1 hexane/CH₂Cl₂) to afford theabove named aldehyde 5.

EXAMPLE 6 1-(1-Thiophen-2-yl-methylcyclobutyl)but-2-yn-1-ol (6)

A solution of propylmagnesium bromide (360 mL of a 0.5M solution in THF,0.180 mmol; 0.5 M in THF) was added dropwise to a solution of aldehyde 5(7.0 g, 36 mmol) in THF (200 mL) while the mixture was maintained atambient temperature. After having stirred 3 h at 23° C., the reactionwas poured into saturated aqueous NH₄Cl and extracted with Et₂O. Theorganic portion was separated and was washed with saturated aqueousNaHCO₃, brine, then dried (Na₂SO₄) and concentrated in vacuo. FCC(silica gel, 100% hexane followed by 1:1, hexane/CH₂Cl₂) gave 6.2 g ofthe above named alkyne 6.

EXAMPLE 7 1-(1-Thiophen-2-yl-methylcyclobutyl)but-3-yn-1-ol (7)

A dry round bottom flask was charged with potassium hydride (5.5 g, 48mmol; 35% by wt dispersion in oil) and the oil was removed by hexanerinse (3×). Aminopropylamide (39 mL) was added to the mixture and it wasstirred until effervescence ceased. The mixture was then cooled to 0° C.and the alkyne 6 (2 g, 9.1 mmol) was added and the reaction stirred at23° C. for 1 h. The reaction was quenched with MeOH (2 mL) and water.The mixture was extracted with Et₂O (3×) and the combined organic layerwas washed with 1N HCl, brine, dried (Na₂SO₄) and concentrated in vacuo.FCC (silica gel, 1:1 hexane/CH₂Cl₂) gave 570 mg of the above namedalkyne 7.

EXAMPLE 8tert-Butyldimethyl[1-(1-thiophen-2-yl-methylcyclobutyl)but-3-ynyloxy]silane(8)

To a cooled (0° C.) solution of alkyne 7 (200 mg, 0.9 mmol), CH₂Cl₂ (5mL) and triethylamine (275 mg, 2.72 mmol) was addedtert-butyldimethylsilyl trifluoromethanesulfonate (360 mg, 1.36 mmol)dropwise. After having stirred for 5 min at 0° C., the mixture waswarmed to 23° C. and stirred an additional hour. The reaction was thenquenched with saturated aqueous NaHCO₃ and extracted with CH₂Cl₂ (2×).The combined organics were washed with 1N HCl, saturated aqueous NaHCO₃,brine then were dried (Na₂SO₄), filtered and concentrated in vacuo. FCC(silica gel, 100% hexane) gave 695 mg of the above named compound 8.

EXAMPLE 9tert-Butyl-[(E)-4-iodo-1-(1-thiophen-2-ylmethylcyclobutyl)but-3-enyloxy]dimethylsilane(9)

Cp₂ZrHCl (304 mg, 1.18 mmol) was added to a solution of alkyne 8 (263mg, 0.786 mmol) in CH₂Cl₂ (5 mL) at 23° C. and stirring was maintainedfor 20 min. N-iodosuccinimide (247 mg, 1.18 mmol) was added to themixture and stirring was continued for an additional 30 min. The mixturewas concentrated in vacuo, diluted with hexane/Et₂O, filtered andconcentrated in vacuo. FCC (silica gel, 100% hexane) gave 360 mg of theabove named compound 9.

EXAMPLE 107-[(R)-3-(tert-Butyldimethylsilanyloxy)-5-oxo-cyclopent-1-enyl]heptanoicacid methyl ester (10)

The named compound was purchased from Nissan Chemical Industries, LTD,Tokyo 101-0054 Japan.

EXAMPLE 117-{(1R,2R,3R)-2-[(E)-(tert-Butyldimethylsilanyloxy)-(1-thiophen-2-yl-methylcyclobutyl)but-1-enyl]-3-[(dimethylethyl)dimethylsilanyloxy]-5-oxo-cyclopentyl}heptanoicacid methyl ester (11)

To a solution of vinyl iodide 9 (120 mg, 0.259 mmol) in Et₂O (1.5 mL) at−78° C. was added t-BuLi (0.35 mL of a 1.5M solution in THF, 0.52 mmol).After the mixture had stirred 30 min at −78° C. 2-thienyl(cyano)copperlithium (1.14 mL, 0.285 mmol) was added and stirring was continued foran additional 30 min. The reaction was then treated with a solution ofthe enone 10 (91.6 mg, 0.259 mmol) in Et₂O (1 mL). After several minuteshad passed, the reaction had solidified and 0.5 mL Et₂O was added. Thereaction was stirred 1 h at −78° C., was poured into saturated aqueousNH₄Cl and then was extracted with EtOAc (3×). The combined organicportions were washed with brine, filtered and concentrated in vacuo. FCC(silica gel, 100% hexane; 9:1 hexane/EtOAc) gave 63 mg of the abovenamed compound 11.

EXAMPLE 127-{(1R,2R,3R)-3-Hydroxy-2-[(E)-4-hydroxy-4-(1-thiophen-2-yl-methyl-cyclobutyl)but-1-enyl]-5-oxo-cyclopentyl}heptanoic acid methyl ester(12H) 7-{(1R,2R,3R)-3-Hydroxy-2-[(E)-4-hydroxy-4-(1-thiophen-2-yl-methyl-cyclobutyl)but-1-enyl]-5-oxo-cyclopentyl}heptanoic acid methyl ester(12L)

Hydrogen fluoride-pyridine (0.091 mL) was added to a solution of thebis-TBS ether 11 (63 mg, 0.912 mmol) in CH₃CN (3 mL) at 23° C. Afterhaving stirred for 3 h, the mixture was quenched with saturated aqueousNa₂CO₃ and extracted with EtOAc (3×). The combined organic portions werewashed with 1N HCl, saturated aqueous NaHCO₃, brine, and were then dried(Na₂SO₄), filtered and concentrated in vacuo. FCC (silica gel, 3:2hexane/EtOAc followed by 1:1 hexane/EtOAc) gave a higher R_(f) diol (10mg) and a lower R_(f) diol (30 mg), hereinafter, designated as namedcompounds 12H and 12L, respectively).

EXAMPLE 13H 7-{(1R,2R,3R)-3-Hydroxy-2-[(E)-4-hydroxy-4-(1-thiophen-2-yl-methylcyclobutyl)but-1-enyl]-5-oxocyclopentyl}heptanoic acid (13H)

methyl ester 12H (4.8 mg, 10.4 mmol) and PLE (0.134 mmol, 45 mmol) werestirred in phosphate buffer (2 mL, pH 7.2) at 23° C. over 16 h. Afterthe reaction was complete, the mixture was filtered and the aqueousphase was extracted with EtOAc (3×). The combined organic phases werewashed with brine, dried (Na₂SO₄), filtered and concentrated in vacuo.FCC (silica gel, 11: hexane/EtOAc; EtOAc) gave of the above named acid13H.

EXAMPLE 13L7-{(1R,2R,3R)-3-Hydroxy-2-[(E)-4-hydroxy-4-(1-thiophen-2-yl-methyl-cyclobutyl)but-1-enyl]-5-oxo-cyclopentyl}heptanoic acid (13L)

methyl ester 12L was reacted according to Example 13H to yield the abovenamed compound.

EXAMPLE 14(Z)-7-[(R)-3-(tert-Butyldimethylsilanyloxy)-5-oxo-cyclopent-1-enyl]hept-5-enoicacid methyl ester (14)

The named compound was purchased from Nissan Chemical Industries, LTD,Tokyo 101-0054 Japan.

EXAMPLE 15(Z)-7-{(1R,2R,3R)-2-[(E)-(tert-Butyldimethylsilanyloxy)-(1-thiophen-2-yl-methylcyclobutyl)but-1-enyl]-3-[(dimethylethyl)dimethylsilanyloxy]-5-oxo-cyclopentyl}hept-5-enoicacid methyl ester (15)

The compound of Example 14, above, was reacted in accordance with theprocess of Example 11 to yield the above named compound.

EXAMPLE 16(Z)-7-{(1R,2R,3R)-3-Hydroxy-2-[(E)-4-hydroxy-4-(1-thiophen-2-yl-methylcyclobutyl)but-1-enyl]-5-oxo-cyclopentyl}hept-5-enoic acid methylester (16H)(Z)-7-{(1R,2R,3R)-3-Hydroxy-2-[(E)-4-hydroxy-4-(1-thiophen-2-yl-methylcyclobutyl)but-1-enyl]-5-oxo-cyclopentyl}hept-5-enoic acid methylester (16L)

The compound of Example 15 is reacted in accordance with the process ofExample 12 to yield a higher R_(f) diol (6.0 mg) and a lower R_(f) diol(6.0 mg), hereinafter, designated as 16H and 16L, respectively.

EXAMPLE 17H(Z)-7-{(1R,2R,3R)-3-Hydroxy-2-[(E)-4-hydroxy-4-(1-thiophen-2-yl-methylcyclobutyl)but-1-enyl]-5-oxo-cyclopentyl}hept-5-enoic acid (17H)

The compound 16H of Example 16 is reacted in accordance with the processof Example 13H to yield the above named compound.

EXAMPLE 17L(Z)-7-{(1R,2R,3R)-3-Hydroxy-2-[(E)-4-hydroxy-4-(1-thiophen-2-yl-methylcyclobutyl)but-1-enyl]-5-oxo-cyclopentyl}hept-5-enoic acid (17L)

The compound 16L of Example 16 is reacted in accordance with the processof Example 13H to yield the above named compound.

EXAMPLE 187-{(1R,2R,3R)-3-Hydroxy-2-[(E)-4-hydroxy-4-(1-(5-chloro-thiophen-2-yl-methylcyclobutyl)but-1-enyl]-5-chloro-cyclopentyl}hept-5-enoicacid methyl ester (18H and 18L)

Examples 14 through 16 is repeated with the appropriate chloroderivative replacing(Z)-7-[(R)-3-(tert-Butyldimethylsilanyloxy)-5-oxo-cyclopent-1-enyl]hept-5-enoicacid methyl ester 14 and the appropriate chlorothienyl derivativereplacing 2-thienyl(cyano)copper lithium to yield a product which isseparated to provide a higher R_(f) diol and a lower R_(f) dioldesignated as 18H and 18L, respectively.

EXAMPLE 19H7-{(1R,2R,3R)-3-Hydroxy-2-[(E)-4-hydroxy-4-(1-(5-chloro-thiophen-2-yl)-methyl-cyclobutyl)but-1-enyl]-5-chloro-cyclopentyl}hept-5-enoicacid (19H)

The compound of Example 18H is reacted according to the process ofExample 13H to yield the named compound.

EXAMPLE 19L7-{(1R,2R,3R)-3-Hydroxy-2-[(E)-4-hydroxy-4-(1-(5-chloro-thiophen-2-yl)-methyl-cyclobutyl)but-1-enyl]-5-chloro-cyclopentyl}hept-5-enoicacid (19L)

The compound of Example 18L is reacted according to the process ofExample 13L to yield the named compound.

EXAMPLE 207-{(1R,2R,3R)-3-Hydroxy-2-[(E)-4-hydroxy-4-(1-(5-chloro-thiophen-2-yl)-methyl-cyclobutyl)but-1-enyl]-5-fluoro-cyclopentyl}hept-5-enoicacid methyl ester (20H and 20L)

Examples 14 through 16 is repeated with the appropriate fluoroderivative replacing(Z)-7-[(R)-3-(tert-Butyldimethylsilanyloxy)-5-oxo-cyclopent-1-enyl]hept-5-enoicacid methyl ester 14 and the appropriate chlorothienyl derivativereplacing 2-thienyl(cyano)copper lithium to yield a product which isseparated to provide a higher R_(f) diol and a lower R_(f) dioldesignated as 20H and 20L, respectively.

EXAMPLE 21H7-{(1R,2R,3R)-3-Hydroxy-2-[(E)-4-hydroxy-4-(1-(5-chloro-thiophen-2-yl)-methyl-cyclobutyl)but-1-enyl]-5-fluoro-cyclopentyl}hept-5-enoicacid (21H)

The compound of Example 20H is reacted according to the process ofExample 13H to yield the named compound.

EXAMPLE 21L7-{(1R,2R,3R)-3-Hydroxy-2-[(E)-4-hydroxy-4-(1-(5-chloro-thiophen-2-yl)-methyl-cyclobutyl)but-1-enyl]-5-fluoro-cyclopentyl}hept-5-enoicacid (21L)

The compound of Example 20L is reacted according to the process ofExample 13L to yield the named compound.

EXAMPLE 227-{(1R,2R,3R)-3-Hydroxy-2-[(E)-4-hydroxy-4-(1-(5-chloro-thiophen-2-yl)-methyl-cyclobutyl)but-1-enyl]-cyclopentenyl}hept-5-enoicacid methyl ester

Examples 14 through 16 is repeated with the appropriate nor ketoderivative replacing(Z)-7-[(R)-3-(tert-Butyldimethylsilanyloxy)-5-oxo-cyclopent1-enyl]hept-5-enoic acid methyl ester 14 and the appropriatechlorothienyl derivative replacing 2-thienyl(cyano)copper lithium toyield a product which is separated to provide a higher R_(f) diol and alower R_(f) diol designated as 22H and 22L, respectively.

EXAMPLE 23H7-{(1R,2R,3R)-3-Hydroxy-2-[(E)-4-hydroxy-4-(1-(5-chloro-thiophen-2-yl)-methyl-cyclobutyl)but-1-enyl]-cyclopentenyl}hept-5-enoicacid (23H)

The compound of Example 22H is reacted according to the process ofExample 13H to yield the named compound.

EXAMPLE 23L7-{(1R,2R,3R)-3-Hydroxy-2-[(E)-4-hydroxy-4-(1-(5-chloro-thiophen-2-yl)-methyl-cyclobutyl)but-1-enyl]-cyclopentenyl}hept-5-enoicacid (23L)

The compound of Example 22L is reacted according to the process ofExample 13L to yield the named compound.

Radioligand Binding

Recombinant EP₂ receptor; transient transfectants COS-7 cells weretransiently transfected using Lipofectin (Gibco-BRL life Technologies,Gaitherburg, Md., U.S.A.) according to manufacturer's protocols. Forbinding studies, 2×10⁶ cells were plated onto 150 mm dishes 24 h priorto transfection. Each plate was transfected with 50 μg plasmid DNA and50 μL lipofectin. Cells were collected and membranes prepared at 48 hpost-transfection, and frozen at −80° C. until use.

Plasma membrane preparations were thawed at room temperature and used ata final 1 mg/mL concentration in a 500 μL volume. The binding of[³H]-PGE₂ (specific activity 180 C¹ mmol⁻¹) were determined in duplicateand experiments were replicated three times. Incubations were for 60 minat 25° C. and were terminated by the addition of 4 mL of ice-cold 50 μMTRIS-HCl, followed by rapid filtration through Whatman GF/B filters andthree additional 4 mL washes in a cell harvester (Brandel). Competitionstudies were performed using a final concentration of 5 nM [³H]-PGE₂ andnon-specific binding determined with 10 μM of the respective unlabelledprostanoid.

Certain of the above compounds were tested for activity in therecombinant human EP₂ receptor assay described above and the results arereported in Table 1, below. Note Examples 20 and 21 are the unseparatedmixtures of Examples 20H and 20L and 21H and 21L, respectively.

Exam- ple # Structure hEP₂ 18H

4300 18L

5500 19H

 126 19L

 300 22H

NA 22L

NA 23H

 700 23L

2500 20H

5100 20L

NA 21H

 132 21L

 300 20

8100 21

 112

EP₂ activity indicates that the compounds of this invention are usefulin treating asthma, dysmenorrhea as well as glaucoma and loweringintraocular pressure.

Other potential therapeutic applications are in osteoporosis,constipation, renal disorders, sexual dysfunction, baldness, diabetes,cancer and in disorder of immune regulation.

The compounds of the invention may also be useful in the treatment ofvarious pathophysiological diseases including acute myocardialinfarction, vascular thrombosis, hypertension, pulmonary hypertension,ischemic heart disease, congestive heart failure, and angina pectoris,in which case the compounds may be administered by any means that effectvasodilation and thereby relieve the symptoms of the disease. Forexample, administration may be by oral, transdermal, parenterial,subcutaneous, intravenous, intramuscular, intraperitoneal, transdermal,or buccal routes.

The compounds of the invention may be formulated into an ointmentcontaining about 0.10 to 10% of the active ingredient in a suitable baseof, for example, white petroleum, mineral oil and petroleum and lanolinalcohol. Other suitable bases will be readily apparent to those skilledin the art.

The pharmaceutical preparations of the present invention aremanufactured in a manner which is itself known, for example, by means ofconventional dissolving or suspending the compounds, which are alleither water soluble or suspendable. For administration in the treatmentof the other mentioned pathophysiological disorders. The pharmaceuticalpreparations which can be used orally include push-fit capsules made ofgelatin, as well as soft, sealed capsules made of gelatin and aplasticizer such as glycerol or sorbitol. The push-fit capsules cancontain the active compounds in liquid form that may be mixed withfillers such as lactose, binders such as starches, and/or lubricantssuch as talc or magnesium stearate and, optionally, stabilizers. In softcapsules, the active compounds are preferably dissolved or suspended insuitable liquids, such as in buffered salt solution. In addition,stabilizers may be added.

In addition to being provided in a liquid form, for example in gelatincapsule or other suitable vehicle, the pharmaceutical preparations maycontain suitable excipients to facilitate the processing of the activecompounds into preparations that can be used pharmaceutically. Thus,pharmaceutical preparations for oral use can be obtained by adhering thesolution of the active compounds to a solid support, optionally grindingthe resulting mixture and processing the mixture of granules, afteradding suitable auxiliaries, if desired or necessary, to obtain tabletsor dragee cores.

Suitable excipients are, in particular, fillers such as sugars, forexample lactose or sucrose, mannitol or sorbitol, cellulose preparationsand/or calcium phosphates, for example tricalcium phosphate or calciumhydrogen phosphate, as well as inders such as starch, paste using forexample, maize starch, wheat starch, rich starch, potato starch,gelatin, tragacanth, methyl cellulose, hydroxypropylmethylcellulose,sodium carboxymethylcellulose, and/or polyvinyl pyrrolidone. If desired,disintegrating agents may be added such as the above-mentioned starchesand also carboxymethyl-starch, crosslinked polyvinyl pyrrolidone, agar,or algenic acid or a salt thereof, such as sodium alginate. Auxiliariesare, above all, flow-regulating agents and lubricants, for example,silica, talc, stearic acid or salts thereof, such as magnesium stearateor calcium stearate, and/or polyethylene glycol. Dragee cores areprovided with suitable coatings which if desired, are resistant togastric juices. For this purpose, concentrated sugar solutions may beused, which may optionally containing gum arabic, talc, polyvinylpyrrolidone, polyethylene glycol and/or titanium dioxide, lacquersolutions and suitable organic solvents or solvent mixtures. In order toproduce coatings resistant to gastric juices, solutions of suitablecellulose preparations such as acetylcellulose phthalate orhydroxypropylmethyl-cellulose phthalate, are used. Dye stuffs orpigments may be added to the tables or dragee coatings, for example, foridentification or in order to characterize combinations of activecompound doses.

Suitable formulations for intravenous or parenteral administrationinclude aqueous solutions of the active compounds. In addition,suspensions of the active compounds as oily injection suspensions may beadministered. Aqueous injection suspensions may contain substances whichincrease the viscosity of the suspension include, for example, sodiumcarboxymethyl cellulose, soribitol, and/or dextran. Optionally, thesuspension may also contain stabilizers.

The foregoing description details specific methods and compositions thatcan be employed to practice the present invention, and represents thebest mode contemplated. However, it is apparent for one of ordinaryskill in the art that further compounds with the desired pharmacologicalproperties can be prepared in an analogous manner, and that thedisclosed compounds can also be obtained from different startingcompounds via different chemical reactions. Similarly, differentpharmaceutical compositions may be prepared and used with substantiallythe same result. Thus, however detailed the foregoing may appear intext, it should not be construed as limiting the overall scope hereof;rather, the ambit of the present invention is to be governed only by thelawful construction of the appended claims.

1. An ophthalmic solution comprising a therapeutically effective amountof a compound represented by formula I:

wherein the hatched segment represents an α bond, the solid trianglerepresents a β bond, the wavy segment represents α or β bond, dashedlines represent a double bond or a single bond, X is selected from thegroup consisting of hydrogen and halogen radicals, R³ is heteroaryl or asubstituted heteroaryl radical, R¹ and R² are independently selectedfrom the group consisting of hydrogen or a lower alkyl radical having upto six carbon atoms, or a lower acyl radical having up to six carbonatoms, R is selected from the group consisting of CO₂R⁴, CONR⁴ ₂,CH₂OR⁴, CONR⁴SO₂R⁴, P(O)(OR⁴) and

wherein R⁴ is selected from the group consisting of H, phenyl and loweralkyl having from one to six carbon atoms and n is 0 or an integer offrom 1 to 4 or a pharmaceutically acceptable salt thereof, in admixturewith a non-toxic, ophthalmically-acceptable liquid vehicle, package in acontainer suitable for metered application.
 2. The ophthalmic solutionof claim 1 wherein the substituent on the heteroaryl radical is selectedfrom the group consisting of C₁ to C₆ alkyl; OR⁴; CO₂R⁴; halogen,trifluoromethyl; COR⁴; COCF₃; SO₂NR⁴, NO₂; and CN.
 3. The compoundrepresented by formula I:

wherein the hatched segment represents an α bond, the solid trianglerepresents a β bond, the wavy segment represents an α or β bond, dashedlines represent a double bond or a single bond, X is selected from thegroup consisting of hydrogen and halogen radicals, R³ is heteroaryl or asubstituted heteroaryl radical, R¹ and R² are independently selectedfrom the group consisting of hydrogen or a lower alkyl radical having upto six carbon atoms, or a lower acyl radical having up to six carbonatoms, R is selected from the group consisting of CO₂R⁴, CONR⁴ ₂,CH₂OR⁴, CONR⁴SO₂R⁴, P(O)(OR⁴) and

wherein R⁴ is selected from the group consisting of H, phenyl and loweralkyl having from one to six carbon atoms and n is 0 or an integer offrom 1 to
 4. 4. The compound of claim 3 wherein R is CO₂R⁴.
 5. Thecompound of claim 4 wherein R is selected from the group consisting of Hand lower alkyl.